Hydraulic brake control



G. H. WHITNEY ETAL HYDRAULIC BRAKE CONTROL Feb. 12, 1952 2 SHEETS-SHEET 1 Filed Sept. '7, 1948 5 m n A NOV 9 h N h 5 J. Z M 0 Wm 6A W G. H. WHITNEY EI'AL HYDRAULIC BRAKE CONTROL Feb. 12, 1952 2 SHEE'I jS-SHEET 2 Filed Sept. 7, 1948 Guy .H. Whitney Alonzo J. Rosso INVENTORS BY g m Patented Feb. 12, 1952 UNITED STATES PATENT OFFICE HYDRAULIC BRAKE CONTROL Guy H. Whitney, Morrisville, Pa., and Alonzo J. Rosso, Washington Crossing, N, J.

Appiication September 7, 1948, Serial No. 48,054

Particularly, the invention contemplates the,

provision of a locking control for hydraulic brakes on automobiles and similar vehicles, permitting; thebrakes to remain applied or on if desired, after the operator removes his foot from the brake pedal.

The advantages resulting from the use of the invention may be readily appreciated, inasmuch as a vehicle equipped with the invention and with its brakes locked, will be quite convenient to manipulate while starting on hills, and also, will not be so easily stolen or misappropriated by being towed away by unauthorized persons.

An important feature of the invention resides, therefore, in the provision of remotely actuated means for preventing the return of brake fluid to the master cylinder afterthe brakes have been applied, whereby the brakes will not be released, unless the operator wishes to do so.

Another feature of the invention lies in the association of the brake locking control with the ignition system of the vehicle, matters being so arranged that the locking control is inoperative while the engine of the vehicle is running, but becomes energizable when the ignition system is inactive.

A further feature of the invention resides in the association of the locking control with the clutch pedal of the vehicle, this being so arranged that the locking control, normally inactive, becomes energizable upon depression of the clutch pedal.-

Additional advantages of the invention lie in its simplicity of construction, ease and convenience of manipulation, and in its adaptability to automotive vehicles of various types.

With the above more important objects and features in view, and such other objects and features as may become apparent as this specification proceeds, the invention consists essentially of the arrangement and construction of parts as illustrated in the accompanying drawings, in which:

Figure l is a perspective view showing portions of the vehicle brake, clutch and ignition systems, with the invention associated therewith;

Fi re 2 i a c s-sectional view, taken substantial y the p an oi the line 2-4 f Figure. 1;,

Figure 3 is a cross-sectional view, taken substantially in the plane of the line 3-3 of Figure 2;

Figure 4 is a fragmentary perspective view of a floor board and clutch pedal of the vehicle, showing a switch used in the invention as being associated with the clutch pedal;

Figure 5 is a cross-sectional view, taken substantially inrthe plane of the line 55 of Figure 4; and

Figure 6 is a cross-sectional view, taken sub-- stantially in the plane of the line 6--6 of Figure 5,.

Like characters of reference are employed to designate like parts in the specification and throughout the severalviews.

Referring now to the accompanying drawings in detail, the reference character l0 designates a brake pedal of a vehicle connected by means of a link l2 to a conventional master cylinder assembly M, the latter. in turn, communicating through the medium of a pressure transmitting conduit IS with what may be generally referred to as an electro-magnetic valve l8.

This valve, in turn, is connected by further pressure transmitting conduits 20, 22 to the wheel cylinders (not shown) in the conventional, well known manner.

The valve !8 as disclosed in the accompanying nicating with the, bore 26 through the medium,

of the passages 32, 34, respectively, as is best shown in Figure 2.

A substantially tubular insert 40 is positioned in, the bore 26, between the caps 28, 30 and is provided adjacent the cap 30 with an end wall 42, the latter, in turn, beingformed with a fluid passage 44 and being equipped with a normally closed, spring pressed valve unit 46 of theconventional type commonly used in hydraulic brake master cylinders.

It will be apparent from the foregoing that the valve unit 45, when closed, facilitates passage of fluid from the conduit 16 to the conduit 2% but prevents passage. of fluid in a relatively oppositev direction, thatiis, from the conduit, 20. to

the conduit l6. However, electro-magnetically actuated means are provided for opening the valve unit 46, these means including a bellcrank 48 pivotally mounted in the insert 40 as at 58, one arm of this crank being engageable with the stem 52 of the valve unit 46, while the second arm of the bellcrank is operatively connected as at 54 to a reciprocable armature 58 of an electromagnet 58.

The magnet 58 is positioned in a substantially cylindrical housing 60 formed integrally with the valve body 24, the housing or compartment 50 being provided with a removable plug 52 to facilitate installation and possible servicing of the magnet assembly.

One end of the winding of the electro-magnet 58 is grounded, while its remaining end is connected by means of a conductor 54 to a switch assembly 56 which, in turn, is connected in series by a further conductor 68 to the conventional ignition switch 18 of the vehicle on which the invention is used. 7

The switch 66, which may be referred to as a secondary or an auxiliary switch, embodies in its construction a suitable base plate 12 secured to the floor-board 14 adjacent the clutch pedal 16, the switch 56 being disposed at the underside of the floor-board 14, as is best shown in Figure 4.

An insulated block 18 is provided on the base plate 12 and carries a relatively stationary contact arm and point 80 and a resilient, deflectible contact arm and point 82, this being best shown in the accompanying Figure 6.

Moreover, a pair of brackets 84 are mounted on the base plate 12 and provide bearings for an angulated portion 86 of a substantially L-shaped actuating arm 88, the free end portion of the latter being urged in engagement with the underside of the clutch pedal 16 by means of a suitable tension spring 98, as will be clearly apparent from the accompanying drawings. The portion 85 of the arm 88 carries a cam 92 which engages the defiectible contact arm and point 82, and matters are so arranged that when the clutch pedal 16 is in its released position (with the clutch engaged) the cam 92 urges the contact arm and point 82 in engagement with the contact arm and point 88, maintaining the switch 66 closed. However, when the clutch pedal 15 is depressed so as to disengage the clutch, the arm 88 will swing in the direction of the arrow 94 (see Figure 6) and the resiliency of the deflectible contact arm and point 82 is such that the two points 88, 82 will become separated and the switch will be opened.

The mechanism of the switch '5 may be provided with a suitable cover 96 attach d to the base plate 12 and formed with a suitable recess 98 to accommodate the angulated portion 85 of the arm 88, that is, matters are so arranged that;

the cover 96 may be removed for the purpose of inspecting the switch m chanism, without disturbing the arm 88, as will be clearly apparent.

Having thus described the construction of the invention, its method of operation will now be explained.

Assuming the ignition switch Hi to be closed while the engine is running and the clutch engaged, a supply of current will be delivered through the switches and 65 to the electromagnet 58 of the valve I8, and the electromagnet, being energized, will draw the armature 55 thereof upwardly as indicated at Hi9 (see Figure 2), so that the bellcrank 48 will press against the stem 52 of the valve unit 45 and thereby retain the valve unit in an open position.

Under such circumstances, hydraulic fluid may freely travel from the conduit [6 to the conduit 20 and vice versa, in response to the actuation of the master cylinder l4 in the conventional manner.

However, when the engine is stopped by opening the ignition switch H3, energization of the electro-magnet 58 will cease, the armature 56 will drop downwardly under the influence of gravity, and the valve unit 45, responding to its spring I 62, will become closed. However, the spring-pressed valve unit 45 will permit hydraulic fluid to travel from the conduit it to the conduit 28 as has been already explained, and if the operator of the vehicle, after shutting off the engine by the switch 18, depresses the brake pedal l8, hydraulic fluid will travel from the master cylinder l4 to the wheel cylinders and the brakes will be applied. However, since the valve unit 46, under such circumstances, will prevent the fluid from traveling back to the master cylinder, the brakes will remain appliedas long as the switch 10 remains open, even if the operator of the vehicle removes his foot from the brake pedal i 8. It will thus be apparent that the invention will permit the operator to leave the vehicle with the hydraulic brakes applied,"

thus minimizing the possibility of the vehicle being towed away by unauthorized persons.

starting the engine on inclined roads, this being accomplished by simply leaving the ignition switch 10 closed (with the engine running) and depressing the clutch pedal 16. This action will result in the switch 66 becoming open, thus closing the valve ill in much the same manner as when the ignition switch 70 was opened, as described in the preceding paragraphs. Thereafter, while depressing the clutch pedal l6 with his left foot and first applying the brakes with his right foot, the brakes will remain applied, permitting the operator to remove his right foot to the starter pedal (not shown), if the engine of the vehicle should be stopped or become stalled on a hill.

Needless to say, the valve ill will be opened automatically as soon as the clutch pedal 16 is returned to its engaged position, thereby simultaneously releasing the hydraulic brake system.

It is believed that the advantages and use of the invention will be clearly apparent from the foregoing disclosure and, accordingly, further description thereof at this point is deemed tioned. intermediate the ends of the chamber,

and provided at one of its ends with a Wall having a valve port therein, the remaining end and the adjacent upper portion of said insert be n open, an end cap provided in each end ofsaid chamber and having a iluid carrying tube connected thereto in communication with the chamber, a spring-pressed closure element adapted to seat against said Wall and including a stem slidable through said port, a transverse fulcrum pin provided in the open end portion of said insert, a bellcrank provided on said pin and having one arm thereof in operating engagement with said stem, a hollow cylindrical member extending upwardly into said compartment and affording a re-entrant pocket communicating at its lower end with said chamber, an electro-magnetic coil wound around said member in said compartment, and a gravity actuated plunger positioned in said pocket and slidable upwardly in response to energization of said coil, the lower end of said plunger being pivotally connected to the second arm of said bellcrank, whereby said stem may he slid to open and close said element by reciprocation of said plunger.

GUY H. WHITNEY. ALONZO J. ROSSO;

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 858,467 Richards July 2, 1907 1,050,431 Darrin Jan. 14, 1913 1,883,957 Koch Oct. 25, 1932 1,990,290 Larkin Feb. 5, 1935. 2,052,246 Ray Aug. 25, 1936 2,148,190 Darling Feb. 21, 1939 2,168,774 Hurlburt Aug. 8, 1939 2,194,276 Carlson Mar. 19, 1940 2,217,141 Sprinkle Oct. 8, 1940 2,262,842 Goepfrich Nov. 18, 1941 2,275,890 Coe Mar. 10, 1942 2,287,301 Freeman June 23, 1942 2,287,562 Pennington June 23, 1942 2,313,232 Freeman Mar. 9, 1943 2,345,280 Morgan Mar. 28, 1944 2,394,215 Stephenson Feb. 5, 1946 

